Camouflage materials are routinely used in hunting and military applications whereby there is a desire to obscure an object from immediate recognition. To fabricate such camouflage materials, conventional textile fabrics, such as cotton-duck, have been practiced and simply printed with a two-dimensional pattern.
The production of conventional textile fabrics is known to be a complex, multi-step process. The production of fabrics from staple fibers begins with the carding process where the fibers are opened and aligned into a feedstock known as sliver. Several strands of sliver are then drawn multiple times on drawing frames to further align the fibers, blend, improve uniformity as well as reduce the diameter of the sliver. The drawn sliver is then fed into a roving frame to produce roving by further reducing its diameter as well as imparting a slight false twist. The roving is then fed into the spinning frame where it is spun into yarn. The yarns are next placed onto a winder where they are transferred into larger packages. The yarn is then ready to be used to create a fabric.
For a woven fabric, the yarns are designated for specific use as warp or fill yarns. The fill yarn packages (which run in the cross direction and are known as picks) are taken straight to the loom for weaving. The warp yarns (which run on in the machine direction and are known as ends) must be further processed. The packages of warp yarns are used to build a warp beam. Here the packages are placed onto a warper, which feeds multiple yarn ends onto the beam in a parallel array. The warp beam yarns are then run through a slasher where a water-soluble sizing is applied to the yarns to stiffen them and improve abrasion resistance during the remainder of the weaving or knitting process. The yarns are wound onto a loom beam as they exit the slasher, which is then mounted onto the back of the loom. Here the warp and fill yarns are interwoven or knitted in a complex process to produce yardages of cloth.
Coloring and shading are likewise complex processes in conventional textile production. Colors and patterns of color can be achieved by using yarns of various colors, resulting from the dyeing of the yarn packages themselves. Further, greige goods, yardage produced from undyed yarns, can be dyed in any of several ways common to the industry, such as jet dyeing, and vat dyeing. For application of color and patterns of colors onto the surface of a fabric, screen-printing is commonly used, whereby pigments are applied to the fabrics by a series of engraved rolls where each roll applies a specific color and part of the pattern.
Detailed shading of colors, where more than one hue of a particular major color are apparent in the same fabric, is usually achieved with a yarn that has a blend of fibers, where each of the fibers takes up the color differently in the dyeing process. An example of such a yarn is heather yarns, popular for knitting sweaters.
In contrast, the production of nonwoven fabrics from staple fibers is known to be more efficient than traditional textile processes as the fabrics are produced directly from the carding process. Nonwoven fabrics are suitable for use in a wide variety of applications where the efficiency with which the fabrics can be manufactured provides a significant economic advantage for these fabrics versus traditional textiles. Hydroentangled fabrics have been developed with improved properties that are a result of the entanglement of the fibers or filaments in the fabric providing improved fabric integrity. U.S. Pat. No. 3,485,706, to Evans, hereby incorporated by reference, discloses processes for effecting hydroentanglement of nonwoven fabrics. More recently, hydroentanglement techniques have been developed which impart images or patterns to the entangled fabric by effecting hydroentanglement on three-dimensional image transfer devices. Such three-dimensional image transfer devices are disclosed in U.S. Pat. No. 5,098,764, hereby incorporated by reference, with the use of such image transfer devices being desirable for providing a fabric with enhanced physical properties.
A particularly advantageous application of this patterning technology is the ability to form nonwoven fabrics having a natural or organic texture imparted into the actual fabric at the time of manufacture. Image transfer devices can be utilized which can impart an irregular three-dimensional pattern, which aids in distracting the human eye away from the planar quality of the material. The imparted three-dimensional texture also provides for the ability of the material to cast variable shadows, thus further enhancing the disruptive power of the material. A fabric having such a natural or organics texture in an irregular pattern can be further enhanced in a camouflage application by the use of pre-dyed fibrous components and/or post fabrication dying and printing.